1. Field of the Invention
The present invention relates to a test pattern for measuring semiconductor alloys, and more particularly, to a test pattern for measuring semiconductor alloys using X-ray diffraction (hereinafter abbreviated as XRD) technique.
2. Description of the Prior Art
Semiconductor materials including IV groups, III-V groups, and II-VI groups are important materials used in wide ranges of devices of integrated circuits (ICs). For example, semiconductor alloys such as silicon germanium (SiGe) or silicon carbide (SiC) are grown on a conventional silicon substrate for serving as a recessed or raised source/drain and improving carrier mobility of device by providing stress to the channel region. In order to form a sufficient element for the device, parameters such as thickness, dopant concentration, and strain must be known well. Accordingly, it is always important to measure and monitor the quality of the semiconductor materials.
XRD is commonly used as a practical measuring technique in the research and development in semiconductor manufacturing. By measuring a sample structure formed on a wafer, common parameters such as abovementioned strain, dopant concentration, and thickness of the semiconductor alloy can be obtained by the XRD technique. Therefore, it is in need to improve x-ray signal strength so that the parameters and qualities of the semiconductor alloys are faithfully conveyed.